1. Field of the Invention
This invention relates in general to certain new and useful improvements in an apparatus and method for producing a radius corner of a metal sheet and more particularly, to an apparatus and method of the type stated which utilizes any one of a plurality of selectable die blocks and associated punches with a plate for resiliently supporting the metal sheet.
2. Brief Description of the Prior Art
The apparatus for producing a radius corner i.e. a rounded corner at two intersecting edges of a metal sheet are well known. Generally, in sheet metal operations, it is desirable to remove the sharp right angle corner at each of the four corners of a rectangularly shaped sheet. The standard practice is to use a so-called "radius punch press". This punch press is designed to have a punch with an arcuate corner portion to engage the sheet and sever the corner portion of the sheet. However, the punch on this punch press is fixed and thus, only one particular radius can be achieved at each sheet corner.
The conventional punch presses are usually rather large machines which are not readily moveable. Thus, these machines are adapted for permanent disposition in a particular location. Some of these punch press machines are mechanically operable and use a large diameter flywheel driver by an electric motor. A clutch is interposed between the motor and flywheel and engages the flywheel on actuation of a foot pedal. Other forms of conventional punch presses are hydraulically operated. Moreover, due to the fact that these conventional presses are hydraulically operated or mechanically operated and must be capable of stamping sheets of varying thickness, they are necessarily bulky and heavy in construction and are also quite expensive. As a result, it is difficult for the average sheet metal shop to afford the cost of more than one or two of these machines. Therefore, the average machine shop is limited as to the number of different radius corners which can be produced on metal sheets.